Module: `calc`#

Calculation support for diffractometers

`default_decision_function`(position, solutions)	The default decision function - returns the first solution.
`UnreachableError`(msg, pseudo, physical)	Position is unreachable.
`CalcRecip`(dtype[, engine, sample, lattice, ...])	Reciprocal space calculations

Specific Geometries

`CalcE4CH`(**kwargs)	Geometry: E4CH
`CalcE4CV`(**kwargs)	Geometry: E4CV
`CalcE6C`(**kwargs)	Geometry: E6C
`CalcK4CV`(**kwargs)	Geometry: K4CV
`CalcK6C`(**kwargs)	Geometry: K6C
`CalcPetra3_p09_eh2`(**kwargs)	Geometry: PETRA3 P09 EH2
`CalcPetra3_p23_4c`(**kwargs)	Geometry: PETRA3 P23 4C
`CalcPetra3_p23_6c`(**kwargs)	Geometry: PETRA3 P23 6C
`CalcSoleilMars`(**kwargs)	Geometry: SOLEIL MARS
`CalcSoleilNanoscopiumRobot`(**kwargs)	Geometry: SOLEIL NANOSCOPIUM ROBOT
`CalcSoleilSiriusKappa`(**kwargs)	Geometry: SOLEIL SIRIUS KAPPA
`CalcSoleilSiriusTurret`(**kwargs)	Geometry: SOLEIL SIRIUS TURRET
`CalcSoleilSixsMed1p2`(**kwargs)	Geometry: SOLEIL SIXS MED1+2
`CalcSoleilSixsMed2p2`(**kwargs)	Geometry: SOLEIL SIXS MED2+2
`CalcSoleilSixsMed2p3`(**kwargs)	Geometry: SOLEIL SIXS MED2+3
`CalcSoleilSixsMed2p3v2`(**kwargs)	Geometry: SOLEIL SIXS MED2+3 v2
`CalcZaxis`(**kwargs)	Geometry: ZAXIS

class hkl.calc.CalcE4CH(**kwargs)[source]#: Geometry: E4CH

class hkl.calc.CalcE4CV(**kwargs)[source]#: Geometry: E4CV

class hkl.calc.CalcE6C(**kwargs)[source]#: Geometry: E6C

class hkl.calc.CalcK4CV(**kwargs)[source]#: Geometry: K4CV

class hkl.calc.CalcK6C(**kwargs)[source]#: Geometry: K6C

class hkl.calc.CalcPetra3_p09_eh2(**kwargs)[source]#: Geometry: PETRA3 P09 EH2

class hkl.calc.CalcPetra3_p23_4c(**kwargs)[source]#: Geometry: PETRA3 P23 4C

class hkl.calc.CalcPetra3_p23_6c(**kwargs)[source]#: Geometry: PETRA3 P23 6C

class hkl.calc.CalcRecip(dtype, engine='hkl', sample='main', lattice=None, degrees=True, units='user', lock_engine=False, inverted_axes=None)[source]#

Reciprocal space calculations

`add_sample`(sample[, select])	Add an HklSample
`calc_linear_path`(start, end, n[, num_params])	Construct a trajectory from start to end with n steps (n+1 points).
`energy`	The energy associated with the geometry, in keV
`engine`
`engine_locked`	If set, do not allow the engine to be changed post-initialization
`engines`
`forward`(position[, engine])	Calculate real positions from pseudo positions.
`forward_iter`(start, end, max_iters, *[, ...])	Iteratively attempt to go from a pseudo start -> end position
`geometry_name`	Name of this geometry, as defined in libhkl.
`geometry_table`([rst])	Describe this geometry in a table.
`get_path`(start[, end, n, path_type])
`inverse`(real)	Calculate pseudo positions from real positions.
`inverted_axes`	The physical axis names to invert
`new_sample`(name[, select])	Convenience function to add a sample by name
`parameters`
`physical_axes`	Physical (real) motor positions as an OrderedDict
`physical_axis_names`
`physical_positions`	Physical (real) motor positions
`Position`	Dynamically-generated physical motor position class
`pseudo_axes`	Ordered dictionary of axis name to position
`pseudo_axis_names`	Pseudo axis names from the current engine
`pseudo_positions`	Pseudo axis positions/values from the current engine
`sample`	Currently selected sample.
`sample_name`	The name of the currently selected sample.
`units`	The units used for calculations
`update`()	Calculate the pseudo axis positions from the real axis positions
`wavelength`	The wavelength associated with the geometry, in angstrom

Parameters:

dtype (str) – Diffractometer type (usually specified by a subclass)
engine (str, optional) – ‘hkl’, for example
sample (str, optional) – Default sample name (default: ‘main’)
lattice (Lattice, optional) – Lattice to use with the default sample
degrees (bool, optional) – Use degrees instead of radians (default: True)
units ({'user', }) – The type of units to use internally
lock_engine (bool, optional) – Don’t allow the engine to be changed during the life of this object
inverted_axes (list, optional) – Names of axes to invert the sign

property Position#: Dynamically-generated physical motor position class

_canonical2user(canonical)[source]#: Convert canonical axis names to user (renames).

property _cfg_reciprocal#: Return reciprocal lattice to save as configuration.

_get_axis_by_name(name)[source]#

Given an axis name, return the HklParameter

Parameters:: name (str) – If a name map is specified, this is the mapped name.

_get_path_fcn(path_type)[source]#

_get_sample(name)[source]#

_invert_physical_positions(pos)[source]#

Invert the physical axis positions based on the settings

Parameters:: pos (OrderedDict) – NOTE: Modified in-place

_re_init()[source]#

_repr_info()[source]#

add_sample(sample, select=True)[source]#

Add an HklSample

Parameters:

sample (HklSample instance) – The sample name, or optionally an already-created HklSample instance
select (bool, optional) – Select the sample to focus calculations on

property axes_c#: User-defined real-space axes held constant during forward() calculation.

property axes_r#: User-defined real-space axes used for forward() calculation.

property axes_w#: User-defined real-space axes written by forward() calculation.

calc_linear_path(start, end, n, num_params=0, **kwargs)[source]#

Construct a trajectory from start to end with n steps (n+1 points).

Example (for hkl engine):

>>> e4cv.calc.calc_linear_path((1,1,0), (1,-1,0), 4, num_params=3)
[(1.0, 1.0, 0.0),
(1.0, 0.5, 0.0),
(1.0, 0.0, 0.0),
(1.0, -0.5, 0.0),
(1.0, -1.0, 0.0)]

property energy#: The energy associated with the geometry, in keV

property engine#

property engine_locked#: If set, do not allow the engine to be changed post-initialization

property engines#

forward(position, engine=None)[source]#: Calculate real positions from pseudo positions.

forward_iter(start, end, max_iters, *, threshold=0.99, decision_fcn=None)[source]#

Iteratively attempt to go from a pseudo start -> end position

For every solution failure, the position is moved back. For every success, the position is moved closer to the destination.

After up to max_iters, the position can be reached, the solutions will be returned. Otherwise, ValueError will be raised stating the last position that was reachable and the corresponding motor positions.

Parameters:

start (Position)
end (Position)
max_iters (int) – Maximum number of iterations
threshold (float, optional) – Normalized proximity to end position to stop iterating
decision_fcn (callable, optional) –
Function to choose a solution from several. Defaults to picking the first solution. Here is the default decision_fcn():
```
def decision(pseudo_position, solution_list):
    return solution_list[0]
```

Returns:

solutions

Return type:

list

Raises:

UnreachableError (ValueError) – Position cannot be reached The last valid HKL position and motor positions are accessible in this exception instance.

property geometry_name#: Name of this geometry, as defined in libhkl.

geometry_table(rst=False)[source]#

Describe this geometry in a table.

Parameters:: rst (bool) – When True, format using restructured text. Otherwise, use a simpler representation

get_path(start, end=None, n=100, path_type='linear', **kwargs)[source]#

inverse(real)[source]#: Calculate pseudo positions from real positions.

property inverted_axes#: The physical axis names to invert

new_sample(name, select=True, **kwargs)[source]#

Convenience function to add a sample by name

Keyword arguments are passed to the new HklSample initializer.

Parameters:

name (str) – The sample name
select (bool, optional) – Select the sample to focus calculations on

property parameters#

property physical_axes#: Physical (real) motor positions as an OrderedDict

property physical_axis_names#

property physical_positions#: Physical (real) motor positions

property pseudo_axes#: Ordered dictionary of axis name to position

property pseudo_axis_names#: Pseudo axis names from the current engine

property pseudo_positions#: Pseudo axis positions/values from the current engine

property sample#: Currently selected sample.

property sample_name#: The name of the currently selected sample.

property units#: The units used for calculations

update()[source]#: Calculate the pseudo axis positions from the real axis positions

property wavelength#: The wavelength associated with the geometry, in angstrom

class hkl.calc.CalcSoleilMars(**kwargs)[source]#: Geometry: SOLEIL MARS

class hkl.calc.CalcSoleilNanoscopiumRobot(**kwargs)[source]#: Geometry: SOLEIL NANOSCOPIUM ROBOT

class hkl.calc.CalcSoleilSiriusKappa(**kwargs)[source]#: Geometry: SOLEIL SIRIUS KAPPA

class hkl.calc.CalcSoleilSiriusTurret(**kwargs)[source]#: Geometry: SOLEIL SIRIUS TURRET

class hkl.calc.CalcSoleilSixsMed1p2(**kwargs)[source]#: Geometry: SOLEIL SIXS MED1+2

class hkl.calc.CalcSoleilSixsMed2p2(**kwargs)[source]#: Geometry: SOLEIL SIXS MED2+2

class hkl.calc.CalcSoleilSixsMed2p3(**kwargs)[source]#: Geometry: SOLEIL SIXS MED2+3

class hkl.calc.CalcZaxis(**kwargs)[source]#: Geometry: ZAXIS

exception hkl.calc.UnreachableError(msg, pseudo, physical)[source]#

Position is unreachable.

pseudo#

Last reachable pseudo position in the trajectory

Type:: sequence

physical#

Corresponding physical motor positions

Type:: sequence

hkl.calc.default_decision_function(position, solutions)[source]#: The default decision function - returns the first solution.

Module: calc#

Module: `calc`#